Skip to main content
U.S. flag

An official website of the United States government

Open-sight Alidades

By Administration
Image: Open-sight Alidades
Original Thumbnail Medium

Detailed Description

Open-sight Alidades. This type of alidade is a straightedge with a sighting device parallel to the edge. Early alidades were simple bars with open sights on either end, while telescopic alidades were introduced in the early 1800s. The examples here of solid brass and an early plastic/wood combination.
Object ID: USGS-000629, USGS-000631

Sources/Usage

Public Domain.